U.S. patent number 10,815,378 [Application Number 16/127,671] was granted by the patent office on 2020-10-27 for polyamic acid resin and polyamideimide film.
This patent grant is currently assigned to SK Global Chemical Co., Ltd., SK IE Technology Co., Ltd., SK Innovation Co., Ltd.. The grantee listed for this patent is SK Global Chemical Co., Ltd., SK IE Technology Co., Ltd., SK Innovation Co., Ltd.. Invention is credited to Tae Sug Jang, Hyeon Jeong Kim, Jin Hyung Park, Sang Yoon Park.
United States Patent |
10,815,378 |
Kim , et al. |
October 27, 2020 |
Polyamic acid resin and polyamideimide film
Abstract
Provided are a polyamic acid resin derived from an aromatic
diamine, an aromatic dianhydride, a cycloaliphatic dianhydride and
an aromatic diacid dichloride, and a polyamideimide film including
polyamideimide derived from an aromatic diamine, an aromatic
dianhydride, a cycloaliphatic dianhydride and an aromatic diacid
dichloride.
Inventors: |
Kim; Hyeon Jeong (Daejeon,
KR), Park; Sang Yoon (Daejeon, KR), Jang;
Tae Sug (Daejeon, KR), Park; Jin Hyung (Daejeon,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
SK Innovation Co., Ltd.
SK Global Chemical Co., Ltd.
SK IE Technology Co., Ltd. |
Seoul
Seoul
Seoul |
N/A
N/A
N/A |
KR
KR
KR |
|
|
Assignee: |
SK Innovation Co., Ltd. (Seoul,
KR)
SK Global Chemical Co., Ltd. (Seoul, KR)
SK IE Technology Co., Ltd. (Seoul, KR)
|
Family
ID: |
1000005141137 |
Appl.
No.: |
16/127,671 |
Filed: |
September 11, 2018 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20190077960 A1 |
Mar 14, 2019 |
|
Foreign Application Priority Data
|
|
|
|
|
Sep 12, 2017 [KR] |
|
|
10-2017-0116249 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G
73/1007 (20130101); C08G 73/1067 (20130101); C08G
73/1042 (20130101); C08G 73/14 (20130101); C08G
73/1039 (20130101); G02F 1/0063 (20130101); C08L
79/08 (20130101); C08L 2203/16 (20130101); G02F
2203/01 (20130101) |
Current International
Class: |
C08G
73/14 (20060101); G02F 1/00 (20060101); C08G
73/10 (20060101); C08L 79/08 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Listvoyb; Gregory
Attorney, Agent or Firm: The Webb Law Firm
Claims
What is claimed is:
1. A polyamideimide film comprising polyamideimide derived from an
aromatic diamine, an aromatic dianhydride, a cycloaliphatic
dianhydride and an aromatic diacid dichloride, wherein the
cycloaliphatic dianhydride includes a compound represented by the
following Chemical Formula 1, wherein a content of the aromatic
dianhydride is 5 to 25 mol of 4,4'-hexafluoroisopropylidene
diphthalic anhydride and 5 to 25 mol of biphenyltetracarboxylic
dianhydride, based on 100 mol of the aromatic diamine, and the
polyamideimide film has a total light transmittance of 88% or more,
and a light transmittance measured at 388 nm of 40% or less:
##STR00011## wherein R.sub.1 to R.sub.4 are independently of one
another, selected from the group consisting of hydrogen, halogen, a
C.sub.1 to C.sub.10 alkyl group or a C.sub.1 to C.sub.10 alkoxy
group.
2. The polyamideimide film of claim 1, wherein the aromatic diamine
includes 2,2'-bis(trifluoromethyl)-benzidine.
3. The polyamideimide film of claim 1, wherein the aromatic diacid
dichloride includes terephthaloyl dichloride.
4. The polyamideimide film of claim 1, wherein a content of the
aromatic diacid dichloride is more than 50 mol, based on 100 mol of
the aromatic diamine.
5. The polyamideimide film of claim 1, wherein a content of the
cycloaliphatic dianhydride is 5 to 30 mol, based on 100 mol of the
aromatic diamine.
6. The polyamideimide film of claim 1, wherein the polyamideimide
film has a modulus of 5.0 GPa or more, as measured at an extension
speed of 25 mm/min using UTM 3365 available from Instron.
7. The polyamideimide film of claim 1, wherein the polyamideimide
film has a yellow index of 3.0 or less, as measured in accordance
with the ASTM E313 standard.
8. The polyamideimide film of claim 6, wherein the polyamideimide
film has a modulus of 5.0 GPa or more, as measured at an extension
speed of 25 mm/min using UTM 3365 available from Instron, for a
specimen having a thickness of 55 .mu.m, a length of 50 mm and a
width of 10 mm.
9. The polyamideimide film of claim 1, wherein the polyamideimide
film has a total light transmittance of 88% or more, based on a
thickness of 55 .mu.m.
10. The polyamideimide film of claim 7, wherein the polyamideimide
film has a yellow index of 3.0 or less, as measured in accordance
with the ASTM E313 standard, based on a thickness of 55 .mu.m.
11. The polyamideimide film of claim 1, wherein the polyamideimide
film has a light transmittance measured at 388 nm of 40% or less,
based on a thickness of 55 .mu.m.
12. An image display device comprising the polyamideimide film of
claim 1.
Description
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to Korean Patent Application No.
10-2017-0116249 filed Sep. 12, 2017, the disclosure of which is
hereby incorporated in its entirety by reference.
TECHNICAL FIELD
The following disclosure relates to a polyamic acid resin and a
polyamideimide film. More particularly, the following disclosure
relates to a polyamic acid resin derived from a combination of
specific components, and a polyamideimide film including
polyamideimide derived therefrom, having adjusted optical
properties and being capable of implementing a high modulus.
BACKGROUND
In general, polyimide has excellent mechanical and thermal
properties, thereby being applied to various fields including an
insulating substrate field for forming circuits and devices.
However, since a charge transfer complex is formed between aromatic
rings at the time of polymerization to cause polyimide to be brown
or yellow colored, leading to low light transmittance in the
visible light region, it is difficult to apply the polyimide to
display materials.
As a method of improving the light transmittance of the polyimide
to make the polyimide colorless and transparent, a method of using
alicyclic diamine or aliphatic diamine as a diamine component to
inhibit formation of an intramolecular charge transfer complex is
known in the art. Japanese Patent Laid-Open Publication No.
2002-161136 (Patent Document 1) discloses polyimide obtained by
imidizing a polyimide precursor formed by aromatic acid dianhydride
such as pyromellitic dianhydride and trans-1,4-diaminocyclohexane,
however, which represents high transparency but has deteriorated
mechanical physical properties.
As such, as a method for converting the yellow color of polyimide
to be colorless and transparent, an attempt has been made to use
various functional monomers. However, since a polyimide film having
a high light transmittance in the visible light region also has a
high light transmittance value in a short wavelength region of 400
nm or less, when the film is exposed to ultraviolet rays, damage
due to ultraviolet rays occurred in a lower laminate structure of a
display including the polyimide film. In order to solve the
problem, it was intended to use a widely used ultraviolet ray
absorber or ultraviolet ray stabilizer, however, polyimide is
processed at high temperature so that it is hard to use an
additive, and even in the case of using the additive, a yellow
index was increased.
Thus, it is currently needed to develop a technology for polyimide
having excellent inherent mechanical physical properties which is
not deteriorated by implementing a high modulus so that the
polyimide may be applied to various display material fields, and
capable of preventing damage of a lower laminate structure of a
display including a polyimide film due to ultraviolet rays by
decreasing a light transmittance in a short wavelength region of
400 nm or less, so that the coverage may be further broadened.
RELATED ART DOCUMENT
Patent Document
(Patent Document 1) Japanese Patent Laid-Open Publication No.
2002-161136 (Jun. 4, 2002)
SUMMARY
An embodiment of the present invention is directed to providing a
polyamic acid resin and a polyamideimide film which may have
excellent mechanical physical properties simultaneously with a low
yellow index, and have an excellent light transmittance in an
entire wavelength region of visible light and implement a low light
transmittance in a short wavelength region.
In particular, an embodiment of the present invention is directed
to providing a polyamideimide film capable of implementing a high
modulus.
In addition, an embodiment of the present invention is directed to
providing a polyamideimide film capable of preventing ultraviolet
ray-induced damage by ultraviolet ray exposure to a lower structure
of a display including the polyamideimide film.
In one general aspect, a polyamideimide film includes
polyamideimide derived from an aromatic diamine, an aromatic
dianhydride, a cycloaliphatic dianhydride and an aromatic diacid
dichloride, wherein
the cycloaliphatic dianhydride includes a compound represented by
the following Chemical Formula 1, and
the polyamideimide film may have a total light transmittance of 88%
or more, and a light transmittance measured at 388 nm of 40% or
less, as measured in accordance with the ASTM D1003 standard:
##STR00001##
wherein
R.sub.1 to R.sub.4 are independently of one another, selected from
the group consisting of hydrogen, halogen, a C.sub.1 to C.sub.10
alkyl group or a C.sub.1 to C.sub.10 alkoxy group.
According to an exemplary embodiment of the present invention, the
aromatic diamine may include
2,2'-bis(trifluoromethyl)-benzidine.
According to an exemplary embodiment of the present invention, the
aromatic dianhydride may include 4,4'-hexafluoroisopropylidene
diphthalic anhydride and biphenyltetracarboxylic dianhydride.
According to an exemplary embodiment of the present invention, the
aromatic diacid dichloride may include terephthaloyl
dichloride.
According to an exemplary embodiment of the present invention, a
content of the aromatic diacid dichloride may be more than 50 mol,
based on 100 mol of the aromatic diamine.
According to an exemplary embodiment of the present invention, a
content of the aromatic dianhydride may be 10 to 50 mol, based on
100 mol of the aromatic diamine.
According to an exemplary embodiment of the present invention, a
content of the aromatic dianhydride may be 5 to 25 mol of
4,4'-hexafluoroisopropylidene diphthalic anhydride and 5 to 25 mol
of biphenyltetracarboxylic dianhydride, based on 100 mol of the
aromatic diamine.
According to an exemplary embodiment of the present invention, a
content of the cycloaliphatic dianhydride may be 5 to 30 mol, based
on 100 mol of the aromatic diamine.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a modulus of 5.0 GPa or more, as
measured at an extension speed of 25 mm/min using UTM 3365
available from Instron.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a yellow index of 3.0 or less, as
measured in accordance with the ASTM E313 standard.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a modulus of 5.0 GPa or more, as
measured at an extension speed of 25 mm/min using UTM 3365
available from Instron for a specimen having a thickness of 55
.mu.m, a length of 50 mm and a width of 10 mm.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a total light transmittance of 88% or
more, as measured in accordance with the ASTM D1003 standard, based
on a film having a thickness of 55 .mu.m.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a yellow index of 3.0 or less, as
measured in accordance with the ASTM E313 standard, based on a film
having a thickness of 55 .mu.m.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a light transmittance of 40% or less,
as measured at 388 nm, based on a film having a thickness of 55
.mu.m.
In another general aspect, an image display device includes the
polyamideimide film as described above.
In still another general aspect, a polyamic acid resin is derived
from an aromatic diamine, an aromatic dianhydride, a cycloaliphatic
dianhydride and an aromatic diacid dichloride, wherein
the cycloaliphatic dianhydride is represented by the following
Chemical Formula 1:
##STR00002##
wherein
R.sub.1 to R.sub.4 are independently of one another, selected from
the group consisting of hydrogen, halogen, a C.sub.1 to C.sub.10
alkyl group or a C.sub.1 to C.sub.10 alkoxy group.
According to an exemplary embodiment of the present invention, the
aromatic diamine may include
2,2'-bis(trifluoromethyl)-benzidine.
According to an exemplary embodiment of the present invention, the
aromatic dianhydride may include 4,4'-hexafluoroisopropylidene
diphthalic anhydride and biphenyltetracarboxylic dianhydride.
According to an exemplary embodiment of the present invention, the
aromatic diacid dichloride may include terephthaloyl
dichloride.
Other features and aspects will be apparent from the following
detailed description, the drawings, and the claims.
DETAILED DESCRIPTION OF EMBODIMENTS
Hereinafter, the present invention will be described in more detail
with reference to the exemplary embodiments and Examples including
the accompanying drawings. However, the following exemplary
embodiments and Examples are only a reference for describing the
present invention in detail, and the present invention is not
limited thereto, and may be implemented in various forms.
In addition, unless otherwise defined, all technical terms and
scientific terms have the same meanings as those commonly
understood by a person skilled in the art to which the present
invention pertains, the terms used herein is only for effectively
describing a certain exemplary embodiment, and not intended to
limit the present invention.
Throughout the present specification describing the present
invention, unless explicitly described to the contrary,
"comprising" any elements will be understood to imply further
inclusion of other elements rather than the exclusion of any other
elements.
In addition, the singular form used in the specification and claims
appended thereto may be intended to also include a plural form,
unless otherwise indicated in the context.
In addition, "a polyamic acid solution", which is a solution formed
by mixing monomers in an organic solvent, refers to containing a
polyamic acid resin obtained by copolymerization of monomers in the
organic solvent.
The inventors of the present invention provide a polyamideimide
film including an aromatic diamine, an aromatic dianhydride, a
cycloaliphatic dianhydride and an aromatic diacid dichloride. That
is, a modulus may be surprisingly excellent, a yellow index may be
significantly lowered, and a light transmittance over an entire
region of visible light may be raised, by deriving polyamideimide
from a polyamic acid resin having a combination of specific
aromatic diamine, dianhydride and aromatic diacid dichloride. At
the same time, it was found that a polyamideimide film preventing
damage due to ultraviolet rays in a lower structure of a display
including the polyamideimide film may be provided by significantly
decreasing a light transmittance in a short wavelength region,
thereby completing the present invention.
Specifically, in order to provide a resin and a film which may be
applied various display fields by improving optical properties as
well as mechanical and thermal properties, the present invention
provides a polyamic acid resin including specific aromatic diamine,
aromatic dianhydride, cycloaliphatic dianhydride and aromatic
diacid dichloride, and a polyamideimide film derived therefrom.
According to an exemplary embodiment of the present invention, the
present invention relates to a polyamideimide film including
polyamideimide derived from an aromatic diamine, an aromatic
dianhydride, a cycloaliphatic dianhydride and an aromatic diacid
dichloride, wherein
the cycloaliphatic dianhydride includes a compound represented by
the following Chemical Formula 1, and
the polyamideimide film may have a total light transmittance of 88%
or more, and a light transmittance measured at 388 nm of 40% or
less, as measured in accordance with the ASTM D1003 standard:
##STR00003##
wherein
R.sub.1 to R.sub.4 are independently of one another, selected from
the group consisting of hydrogen, halogen, a C.sub.1 to C.sub.10
alkyl group or a C.sub.1 to C.sub.10 alkoxy group.
Preferably, according to an exemplary embodiment of the present
invention, the present invention relates to a polyamideimide film
including polyamideimide derived from an aromatic diamine, an
aromatic dianhydride, a cycloaliphatic dianhydride and an aromatic
diacid dichloride, wherein
the aromatic diamine includes
2,2'-bis(trifluoromethyl)-benzidine,
the aromatic dianhydride may include 4,4'-hexafluoroisopropylidene
diphthalic anhydride and biphenyltetracarboxylic dianhydride,
the cycloaliphatic dianhydride includes a compound represented by
the following Chemical Formula 1, and
the aromatic diacid dichloride includes terephthaloyl
dichloride:
##STR00004##
wherein
R.sub.1 to R.sub.4 are independently of one another, selected from
the group consisting of hydrogen, halogen, a C.sub.1 to C.sub.10
alkyl group or a C.sub.1 to C.sub.10 alkoxy group.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a total light transmittance of 88% or
more, as measured in accordance with the ASTM D1003 standard.
Preferably the total light transmittance may be 89% or more.
Specifically, the total light transmittance may be 88 to 99%. More
preferably, the total light transmittance may be 89 to 95%. Here,
the total light transmittance may be measured, based on a specimen
having a thickness of 55 .mu.m.
In addition, according to an exemplary embodiment of the present
invention, the polyamideimide film may have a light transmittance
of 40% or less, as measured at 388 nm using UV-3600 available from
Shimadzu. Preferably, the light transmittance measured at 388 nm
may be 30% or less. Specifically, the light transmittance measured
at 388 nm may be 1 to 40%. Preferably, the light transmittance
measured at 388 nm may be 5 to 30%. Here, the light transmittance
measured at 388 nm may be measured, based on a specimen having a
thickness of 55 .mu.m.
The polyamideimide film including the polyamideimide by the
combination of the present invention as described above has an
excellent modulus, while significantly lowering a yellow index and
raising a light transmittance over an entire wavelength region of
visible light. At the same time, as the light transmittance is
significantly decreased in a short wavelength region, damage due to
ultraviolet rays in a lower structure of a display including the
polyamideimide film may be prevented without an ultraviolet
additive. In addition, since the ultraviolet additive is not
included, deterioration of physical properties of polyamideimide
may be prevented, and thus, the film is preferred.
According to an exemplary embodiment of the present invention, the
cycloaliphatic dianhydride may include a compound represented by
the following Chemical Formula 1:
##STR00005##
wherein
R.sub.1 to R.sub.4 may be independently of one another, selected
from the group consisting of hydrogen, halogen, a C.sub.1 to
C.sub.10 alkyl group or a C.sub.1 to C.sub.10 alkoxy group.
Preferably, in Chemical Formula 1,
R.sub.1 to R.sub.4 may be independently of one another hydrogen or
a C.sub.1 to C.sub.10 alkyl group.
More preferably, in Chemical Formula 1,
R.sub.1 to R.sub.4 may be independently of one another hydrogen or
a C.sub.1 to C.sub.5 alkyl group.
Most preferably, specifically for example,
1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) may be
included.
When the cycloaliphatic dianhydride is included, a low yellow index
may be implemented, and a light transmittance in a visible light
region may be improved, in the polyamideimide film prepared by the
combination of the aromatic diamine, the aromatic dianhydride and
the aromatic diacid dichloride as described above, which is thus
preferred.
According to an exemplary embodiment of the present invention, a
content of the cycloaliphatic dianhydride may be to 30 mol, based
on 100 mol of the aromatic diamine. Preferably, the content may be
5 to 20 mol. When the cycloaliphatic dianhydride is included at the
content, a yellow index is significantly decreased, and a light
transmittance over an entire wavelength region of visible light may
be raised, which is thus preferred.
The aromatic diamine according to an exemplary embodiment of the
present invention may include 2,2'-bis(trifluoromethyl)-benzidine.
The aromatic diamine may impart excellent optical properties by a
charge transfer effect of fluorine substituents, and
2,2'-bis(trifluoromethyl)-benzidine may provide polyamideimide
which is an imidized product of a polyamic acid resin with a
combination of an aromatic dianhydride, a cycloaliphatic
dianhydride and an aromatic diacid dichloride, thereby implementing
optical properties to be desired depending on a wavelength region,
and also excellent mechanical physical properties.
Here, the aromatic diamine may be used by mixing
2,2'-bis(trifluoromethyl)-benzidine and other known aromatic
diamine components, however, it is more preferred to use
2,2'-bis(trifluoromethyl)-benzidine alone for implementing the
effect to be achieved.
The dianhydride according to an exemplary embodiment of the present
invention includes an aromatic dianhydride and a cycloaliphatic
dianhydride.
The aromatic dianhydride of the present invention is specifically
for example, any one or a mixture of two or more selected from the
group consisting of 4,4'-hexafluoroisopropylidene diphthalic
anhydride (6-FDA), biphenyltetracarboxylic dianhydride (BPDA),
1,2,4,5-benzenetetracarboxylic dianhydride (PMDA),
benzophenonetetracarboxylic dianhydride (BTDA), 4,4'-oxydiphthalic
dianhydride (ODPA), bisdicarboxyphenoxy diphenylsulfide dianhydride
(BDSDA), IBIS-BAN (CAS No. 867350-98-9), TBIS-MPN (CAS No.
933041-59-9) and the like. It is more preferred to use only
4,4'-hexafluoroisopropylidene diphthalic anhydride and
biphenyltetracarboxylic dianhydride for implementing the physical
property effect to be desired.
A content of the aromatic dianhydride according to an exemplary
embodiment of the present invention may be 10 to 50 mol, based on
100 mol of the aromatic diamine. Preferably, the content may be 10
to 40 mol. More preferably, the content may be 20 to 40 mol.
More preferably, a content of the aromatic dianhydride according to
an exemplary embodiment of the present invention may be 5 to 25 mol
of 4,4'-hexafluoroisopropylidene diphthalic anhydride and 5 to 25
mol of biphenyltetracarboxylic dianhydride, based on 100 mol of the
aromatic diamine. Preferably, the content may be 10 to 20 mol of
4,4'-hexafluoroisopropylidene diphthalic anhydride and 10 to 25 mol
of biphenyltetracarboxylic dianhydride. Within the range of the
content, when the polyamideimide film is prepared, the light
transmittance is significantly decreased in a short wavelength
region, and damage due to ultraviolet rays in a lower structure of
a display including the polyamideimide film may be prevented, which
is preferred.
According to an exemplary embodiment of the present invention, the
aromatic diacid dichloride includes terephthaloyl dichloride for
being reacted with the aromatic diamine to form an amide structure
in a high molecular chain. Besides, other known aromatic diacid
dichloride may be further included. Specifically for example, any
one or a mixture of two or more selected from the group consisting
of 1,4-naphthalene dicarboxylic dichloride, 2,6-naphthalene
dicarboxylic dichloride, 1,5-naphthalene dicarboxylic dichloride
and the like may be used. It is preferred to use terephthaloyl
dichloride alone for adjusting optical properties depending on the
range of the polyamideimide film, and also significantly improving
the modulus.
According to an exemplary embodiment of the present invention, a
content of the aromatic diacid dichloride may be more than 50 mol,
based on 100 mol of the aromatic diamine. Preferably, the content
may be 55 mol or more. Specifically, the content may be 55 to 90
mol, preferably 55 to 80 mol, more preferably 55 to 75 mol.
When the content satisfies the range, the physical property balance
to be desired, that is, a high light transmittance over an entire
region of visible light without deteriorating mechanical and
thermal physical properties may be implemented, with the
combination of other components. Besides, by implementing a low
light transmittance even in a short wavelength region of 400 nm or
less, damage due to ultraviolet rays in a lower structure of a
display including the polyamideimide film may be prevented. In
addition, a yellow index may be further decreased, and a
synergistic effect of dramatically improving a modulus may be
implemented.
By copolymerizing a high content of the aromatic diacid dichloride
as described above, the polyamideimide film prepared therefrom has
dramatically improved optical properties, and at the same time may
implement a high modulus, which are preferred.
In particular, there was difficulty in using the aromatic diacid
dichloride at a high content more than 50 mol, based on the diamine
due to gelation and the like during a polymerization reaction.
Thus, conventionally, in order to use the aromatic diacid
dichloride at a high content, lithium chloride, calcium chloride or
the like was used together, however, these compounds leave a
chloride ion to have a bad influence on the environment or
deteriorate the physical properties of the film. In order to solve
the problems, in the present invention, a compositional ratio
depending on a combination with other components including the
aromatic diamine, the aromatic dianhydride and the cycloaliphatic
dianhydride, and a reaction order and a polymerization
concentration of the reaction components may be adjusted to
dramatically increase the content of the aromatic diacid
dichloride, thereby achieving the physical property effect to be
desired.
Since the specific example, content and the like of the
above-described aromatic diamine, aromatic dianhydride,
cycloaliphatic dianhydride and aromatic diacid dichloride are
described above, detailed description will be omitted.
In the present invention, the polyamic acid resin which is a
precursor before preparing polyamideimide may be preferably a resin
produced by copolymerizing an aromatic diamine, an aromatic
dianhydride, a cycloaliphatic dianhydride and an aromatic diacid
dichloride.
Specifically, a polyamic acid resin wherein the aromatic diamine
includes 2,2'-bis(trifluoromethyl)-benzidine, and the aromatic
dianhydride includes 4,4'-hexafluoroisopropylidene diphthalic
anhydride and biphenyltetracarboxylic dianhydride, the
cycloaliphatic dianhydride includes a compound represented by the
following Chemical Formula 1, and the aromatic diacid dichloride
includes terephthaloyl dichloride, may be provided.
##STR00006##
wherein
R.sub.1 to R.sub.4 may be independently of one another, selected
from the group consisting of hydrogen, halogen, a C.sub.1 to
C.sub.10 alkyl group or a C.sub.1 to C.sub.10 alkoxy group.
In the present invention, an equivalent ratio of the aromatic
diamine and a mixture of the aromatic dianhydride, the
cycloaliphatic dianhydride and the aromatic diacid dichloride is
preferably 0.9:1 to 1.1:1, and more preferably 1:1. When the range
is satisfied, the physical properties of the film including the
film forming properties are improved when forming a film from
polyamideimide which is obtained by imidizing the polyamic acid
resin derived from the monomer, which is more preferred.
The polyamic acid resin may be provided as a polyamic acid solution
dissolved in a solvent, and the polyamic acid solution is a
solution of the above-described monomers, and may include an
organic solvent for a solution polymerization reaction. The kind of
the organic solvent is not particularly limited, and specifically
for example, it is preferred to use any one or two or more selected
from the group consisting of dimethylacetamide (DMAc),
N-methyl-pyrrolidone (NMP), dimethylformamide (DMF),
dimethylformsulfoxide (DMSO), acetone, diethylacetamide, m-cresol
and the like.
In the present invention, the polyamic acid solution including the
polyamic acid resin and the solvent may be imidized by further
including any one or two or more selected from the group consisting
of an imidization catalyst and a dehydrating agent, in addition to
the polyamic acid resin.
As the imidization catalyst, any one or more selected from the
group consisting of pyridine, isoquinoline and .beta.-quinoline may
be used. In addition, as the dehydrating agent, any one or more
selected from the group consisting of an acetic anhydride, a
phthalic anhydride and a maleic anhydride may be used, but not
necessarily limited thereto.
Any one or a mixture of two or more selected from the group
consisting of the imidization catalyst and the dehydrating agent
according to an exemplary embodiment of the present invention may
be included at 1 to 5 mol, based on 1 mol of the aromatic
dianhydride and the cycloaliphatic dianhydride. Preferably, 1.5 to
3 mol may be included, but not limited thereto.
In the present invention, the polyamic acid solution may be
imidized to obtain the polyamideimide film. Here, imidization may
be carried out using a known imidization method. Chemical
imidization is preferred. Chemical imidization of the polyamic acid
solution by including pyridine and an acetic anhydride is more
preferred.
The polyamic acid solution according to the present invention may
further include various forms of additives. As the additive, any
one or two or more selected from the group consisting of a flame
retardant, an adhesion improver, inorganic particle, an
antioxidant, an ultraviolet ray inhibitor, a plasticizer, an
antistatic agent and the like may be further included, but not
necessarily limited thereto.
In addition, the present invention provides an image display device
including the above-described polyamideimide film.
The present invention provides a method for preparing a
polyamideimide film including the following steps:
(a) dissolving an aromatic diamine in an organic solvent, then
adding an aromatic dianhydride, a cycloaliphatic dianhydride and an
aromatic diacid dichloride thereto, and performing a reaction to
prepare a polyamic acid solution;
(b) imidizing the polyamic acid solution to prepare polyamideimide;
and
(c) coating a polyamide imide solution in which the polyamideimide
is dissolved in an organic solvent.
In the present invention, the method for preparing a polyamideimide
film is not particularly limited, however, it is preferred to
perform the method using a reactor equipped with a stirrer, a
nitrogen injection apparatus, a dropping apparatus, a temperature
controller and a cooler.
According to an exemplary embodiment of the present invention, step
(a) of preparing a polyamic acid solution may be to add an organic
solvent in a reactor, dissolve an aromatic diamine therein, then
react an aromatic dianhydride and a cycloaliphatic dianhydride, and
then add an aromatic diacid dichloride to perform the reaction.
In addition, another exemplary embodiment of (a) preparing a
polyamic acid solution may be to add an organic solvent to a
reactor, dissolve an aromatic diamine therein, then perform a
reaction with an aromatic diacid dichloride, and then react an
aromatic dianhydride and a cycloaliphatic dianhydride. This is more
preferred, since the content of the aromatic diacid dichloride in a
finally obtained polymer may be increased, that is, polymerization
reaction uniformity is excellent in spite of a high solid content,
and a high modulus may be implemented, in addition to excellent
optical properties.
According to an exemplary embodiment of the present invention, when
preparing the polyamic acid solution, the reaction is performed by
adding the aromatic diamine not altogether, but stepwisely to the
organic solvent, for increasing reactivity. In addition, it is
preferred to firstly add the aromatic diamine to the organic
solvent, and then sufficiently dissolve the aromatic diamine. Here,
the organic solvent to be used is as described above, and it is
preferred to use dimethyl acetamide or N-methyl-2-pyrrolidone. In
addition, the content of the organic solvent may be properly
selected considering the molecular weight of polyamideimide which
is a copolymerized product derived from the monomers, and may be 80
to 97 wt % in the entire composition. The content is preferably 85
to 95 wt %, more preferably 87 to 95 wt %. That is, the solid
content is 3 to 20 wt %, preferably 5 to 15 wt %, and more
preferably 5 to 13 wt %.
When the content of the organic solvent is less than 80 wt %,
gelation may occur during a polymerization process, a uniform
solution may be difficult to be obtained, a solution having a high
viscosity out of an available range is formed, so that purification
using the solvent may not be easy. As such, when the purification
is not done well, optical properties such as a light transmittance
and a yellow index may be deteriorated when forming a film. In
addition, when the content of the organic solvent is more than 97
wt %, solution formation is possible, but the yield of
polyamideimide may be decreased.
Step (a) is performed under an inert gas atmosphere, specifically
for example, with nitrogen or argon gas refluxed in the reactor. In
addition, a reaction temperature range is from room temperature to
80.degree. C., specifically 20 to 80.degree. C., and a reaction
time is 30 minutes to 24 hours, but not limited thereto.
Step (b) of imidization is to imidize the polyamic acid solution
prepared in step (a) to obtain polyamideimide, and a known
imidization method, for example, a thermal imidization method, a
chemical imidization method, and a combination of a thermal
imidization method and a chemical imidization method may be
applied. It is preferred to subject the solution to chemical
imidization, but not limited thereto.
In addition, the imidization may be performed before or after
coating a polyamideimide solution, and applied by the known various
methods, and thus, is not limited.
In the present invention, the chemical imidization may be performed
by further including any one or two or more selected from the group
consisting of an imidization catalyst and a dehydrating agent in
the prepared polyamic acid solution. It is preferred that the
chemical imidization is performed by adding any one or two or more
selected from the group consisting of an imidization catalyst and a
dehydrating agent to the polyamic acid solution prepared in step
(a), in terms of the physical properties of the obtained
polyamideimide. More preferably, any one or two or more selected
from the group consisting of an imidization catalyst and a
dehydrating agent are added to the polyamic acid solution to
perform imidization, and then purification using a solvent is
performed to obtain a solid content, which is dissolved in the
solvent to obtain the polyamideimide solution.
Here, as the dehydrating agent, any one or more selected from the
group consisting of acetic anhydride, phthalic anhydride and maleic
anhydride may be used, and as the imidization catalyst, any one or
more selected from the group consisting of pyridine, isoquinoline
and .beta.-quinoline may be used, but not limited thereto.
According to an exemplary embodiment of the present invention, it
is preferred to use a solvent which may significantly decrease the
solubility of the solid content of polyamideimide, specifically for
example, any one or more selected from the group consisting of
water and alcohol, as the solvent used in the purification after
imidizing the polyamic acid solution.
When the solid content of polyamideimide is obtained by
purification, and then dissolved in the organic solvent to obtain
imidized polyamideimide, as the organic solvent to be used, a
solvent identical to or different from the organic solvent used
when preparing the polyamic acid solution may be used. Here, the
content of the solvent may be 70 to 95 wt %. The content is
preferably 75 to 95 wt %, more preferably 80 to 90 wt %.
In addition, when a viscosity of the polyamideimide solution
prepared by dissolving the finally obtained polyamideimide in the
solvent is measured, the viscosity may be 5,000 to 500,000 cps,
preferably 8,000 to 300,000 cps, more preferably 10,000 to 200,000
cps. Here, the viscosity is measured using a Brookfield viscometer
at 25.degree. C.
The polyamideimide obtained in the present invention has a weight
average molecular weight of 50,000 to 1,000,000 g/mol, preferably
50,000 to 800,000 g/mol, and more preferably 50,000 to 500,000
g/mol. Here, the weight average molecular weight is measured with
polystyrene as a standard sample using 1260 Infinity available from
Agilent Technologies, in which PL gel Olexis was used as a column,
and 4 mg contained in 100 ml of LiCl at 0.5 wt % with DMAc as a
solvent was used as the sample. In addition, the polyamideimide may
have a glass transition temperature of 200 to 400.degree. C.,
preferably 320 to 390.degree. C.
Step (c) of coating a polyamideimide solution in which the
polyamideimide is dissolved in the solvent and subjecting the
coated solution to heat treatment may be further included. The heat
treatment step is to cast the polyamideimide solution on a
substrate such as a glass substrate and subject the cast solution
to heat treatment to form a film. Here, the term "polyamideimide
solution` described in step (c) refers to a coating composition for
preparing a polyamideimide film containing polyamideimide.
According to an exemplary embodiment of the present invention, it
is preferred that the heat treatment is stepwisely performed as an
example. Preferably, the heat treatment may be stepwisely performed
at 80 to 100.degree. C. for 1 minute to 2 hours, at 100 to
200.degree. C. for 1 minute to 2 hours, or at 250 to 300.degree. C.
for 1 minute to 2 hours. More preferably, the stepwise heat
treatment depending on each temperature range is performed for 30
minutes to 2 hours. Here, it is more preferred to perform the
stepwise heat treatment by heating in a range of preferably 1 to
20.degree. C./min when moving to each step. In addition, the heat
treatment may be performed in a separate vacuum oven, but not
necessarily limited thereto.
According to an exemplary embodiment of the present invention, the
coating may be performed using an applicator considering a
thickness of the prepared film to form the film on the substrate,
and the film thickness may be 10 to 100 .mu.m, preferably 20 to 90
.mu.m, but not limited thereto.
According to an exemplary embodiment of the present invention, the
polyamideimide film may have a modulus of 5.0 GPa or more, as
measured at an extension speed of 25 mm/min using UTM 3365
available from Instron. Specifically, the modulus may be 5.0 to 10
GPa, preferably 5.0 to 8.0 GPa. Here, the modulus may be measured,
based on a specimen having a thickness of 55 .mu.m, a length of 50
mm and a width of 10 mm.
In addition, according to an exemplary embodiment of the present
invention, the polyamideimide film may have a total light
transmittance of 88% or more, as measured in accordance with the
ASTM D1003 standard. Preferably the light transmittance may be 89%
or more. Specifically, the total light transmittance may be 88 to
99%. Preferably, the total light transmittance may be 89 to 95%.
Here, the total light transmittance may be measured, based on a
specimen having a thickness of 55 .mu.m.
In addition, according to an exemplary embodiment of the present
invention, the polyamideimide film may have a light transmittance
of 40% or less, as measured at 388 nm using UV-3600 available from
Shimadzu. Preferably, the light transmittance may be 30% or less.
Specifically, the light transmittance measured at 388 nm may be 1
to 40%. Preferably, the light transmittance may be 5 to 30%. Here,
the light transmittance measured at 388 nm may be measured, based
on a specimen having a thickness of 55 .mu.m.
In addition, the polyamideimide film may have a yellow index of
3.00 or less, preferably 2.60 or less, as measured in accordance
with the ASTM E313 standard. Specifically, the yellow index may be
1.00 to 3.00, preferably 1.00 to 2.60. Here, the yellow index is
measured using a ColorQuest XE measuring device available from
HunterLab. In addition, the yellow index may be measured, based on
a specimen having a thickness of 55 .mu.m.
As described above, the polyamideimide film capable of implementing
excellent physical properties may be derived from the aromatic
diamine, the aromatic dianhydride, the cycloaliphatic dianhydride
and the aromatic diacid dichloride. Specifically, the film may be
provided from polyamideimide derived from the polyamic acid resin
wherein the aromatic diamine includes
2,2'-bis(trifluoromethyl)-benzidine, and the aromatic dianhydride
includes 4,4'-hexafluoroisopropylidene diphthalic anhydride and
biphenyltetracarboxylic dianhydride, the cycloaliphatic dianhydride
includes a compound represented by the following Chemical Formula
1, and the aromatic diacid dichloride includes terephthaloyl
dichloride.
##STR00007##
wherein
R.sub.1 to R.sub.4 are independently of one another, selected from
the group consisting of hydrogen, halogen, a C.sub.1 to C.sub.10
alkyl group or a C.sub.1 to C.sub.10 alkoxy group.
The polyamideimide film prepared by the combination may implement
optical properties such as a high total light transmittance and a
low yellow index as described above, and also has an excellent
modulus, and may decrease a light transmittance in a short
wavelength region.
The present invention may manufacture various forms of molded
articles using the polyamideimide. As an example, the present
invention may be applied to a printed wiring board, a flexible
circuit board and the like including a film, a protective film or
an insulating film, but not limited thereto. Preferably, the
present invention may be applied to a protective film which may
replace cover glass, and has a wide application range in various
industrial fields including a display.
Hereinafter, the preferred Examples and Comparative Examples of the
present invention will be described. However, the following
Examples are only a preferred exemplary embodiment, and the present
invention is not limited thereto.
The physical properties of the present invention were measured as
follows:
(1) Light Transmittance (Unit: %)
Total light transmittance of the films prepared in the Examples and
the Comparative Examples were measured using COH-400 available from
Nippon Denshoku in accordance with the ASTM D1003 standard. The
light transmittance at 388 nm of the films prepared in the Examples
and the Comparative Examples were measured using UV-3600 available
from Shimadzu.
(2) Yellow Index
The yellow index of the films prepared in the Examples and the
Comparative Examples was measured in accordance with the ASTM E313
standard using ColorQuest XE (Mode type: Total transmission, Area
view: 0.375 in., UV filter: Nominal) available from HunterLab.
(3) Modulus
The modulus of the films having a length of 50 mm and a width of 10
mm prepared in the Examples and the Comparative Examples was
measured using UTM 3365 available from Instron, under the condition
of pulling at 25 mm/min at 25.degree. C.
(4) Viscosity
The viscosity was measured using a Brookfield viscometer
(Dv2TRV-cone&plate, CPA-52Z) at 25.degree. C.
(5) Molecular Weight
The weight average molecular weight was measured using 1260
Infinity available from Agilent Technologies, with polystyrene as a
standard sample, in which PL gel Olexis was used as the column, and
4 mg contained in 100 ml of LiCl at a concentration of 0.5 wt %
with DMAc as a solvent was used as the sample.
Example 1
Under a nitrogen atmosphere, methylene chloride and
2,2'-bis(trifluoromethyl)-benzidine (TFMB) were added to a reactor
and sufficiently stirred, and then terephthaloyl dichloride (TPC)
was added thereto and stirred for 6 hours to be dissolved and
reacted. Thereafter, an excessive amount of methanol was used for
precipitation and filtration to obtain a reaction product, which
was dried under vacuum at 50.degree. C. for 6 hours or more, and
added again with DMAc to the reactor under the nitrogen atmosphere,
and 4,4'-hexafluoroisopropyllidene diphthalic anhydride (6FDA) was
added thereto and sufficiently stirred until dissolved, and then
biphenyltetracarboxylic dianhydride (BPDA) was added and stirred
until dissolved, and then cyclobutanetetracarboxylic dianhydride
(CBDA) was added and stirred until dissolved. Subsequently,
pyridine and acetic anhydride were added to the solution at
2.5-fold molar amount of the total added amount of dianhydrides,
and stirred at 60.degree. C. for 1 hour. Here, the amount of each
monomer was such that the mole ratio of TFMB:BPDA:CBDA:6FDA:TPC was
100:10:20:15:55, and the solution was adjusted to have a solid
content of 12 wt %. The viscosity of the finally obtained
polyamideimide was 33,000 cps, as measured using a Brookfield
viscometer at 25.degree. C.
The obtained solution was solution-cast on a glass substrate using
an applicator. Thereafter, heat treatment was performed in a vacuum
oven at 100.degree. C. for 30 minutes, at 200.degree. C. for 30
minutes and at 300.degree. C. for 30 minutes, and then cooling was
performed at room temperature, and the film formed on the glass
substrate was separated from the substrate to obtain a
polyamideimide film having a thickness of 55 .mu.m. The result of
measuring the weight average molecular weight of the film was
205,000 g/mol.
Example 2
A polyamideimide film having a thickness of 56 .mu.m was prepared
in the same manner as in Example 1, except that the mole ratio of
TFMB:BPDA:CBDA:6FDA:TPC was 100:20:10:15:55. The weight average
molecular weight of the prepared polyamideimide was 195,000 g/mol,
and the viscosity of the finally obtained polyamideimide was 27,000
cps, as measured using a Brookfield viscometer at 25.degree. C.
Example 3
A polyamideimide film having a thickness of 56 .mu.m was prepared
in the same manner as in Example 1, except that the mole ratio of
TFMB:BPDA:CBDA:6FDA:TPC was 100:10:5:15:70. The weight average
molecular weight of the prepared polyamideimide was 210,000 g/mol,
and the viscosity of the finally obtained polyamideimide was 30,000
cps, as measured using a Brookfield viscometer at 25.degree. C.
Example 4
A polyamideimide film having a thickness of 55 .mu.m was prepared
in the same manner as in Example 1, except that the mole ratio of
TFMB:BPDA:CBDA:6FDA:TPC was 100:15:10:15:60. The weight average
molecular weight of the prepared polyamideimide was 190,000 g/mol,
and the viscosity of the finally obtained polyamideimide was 28,000
cps, as measured using a Brookfield viscometer at 25.degree. C.
Example 5
A polyamideimide film having a thickness of 60 .mu.m was prepared
in the same manner as in Example 1, except that
biphenyltetracarboxylic dianhydride (BPDA) was not used, and the
compound represented by the following Chemical Formula 2 was
further included, so that the mole ratio of
TFMB:TBIS-MPN:CBDA:6FDA:TPC was 100:5:25:15:55. The weight average
molecular weight of the prepared polyamideimide was 195,000 g/mol,
and the viscosity of the finally obtained polyamideimide was 28,000
cps, as measured using a Brookfield viscometer at 25.degree. C.
##STR00008##
Example 6
A polyamideimide film having a thickness of 58 .mu.m was prepared
in the same manner as in Example 1, except that
biphenyltetracarboxylic dianhydride (BPDA) was not used, and the
compound represented by the following Chemical Formula 3 was
further included, so that the mole ratio of
TFMB:TBIS-BAN:CBDA:6FDA:TPC was 100:5:25:15:55. The weight average
molecular weight of the prepared polyamideimide was 170,000 g/mol,
and the viscosity of the finally obtained polyamideimide was 21,000
cps, as measured using a Brookfield viscometer at 25.degree. C.
##STR00009##
Example 7
A polyamideimide film having a thickness of 50 .mu.m was prepared
in the same manner as in Example 1, except that
biphenyltetracarboxylic dianhydride (BPDA) was not used, the mole
ratio of TFMB:CBDA:6FDA:TPC was 100:30:15:55, and 0.15 wt % of a UV
additive (TBO, 2,5-Bis(5-tert-butyl-2-benzoxazolyl)thiophene) was
further included, based on the total amount of the composition. The
weight average molecular weight of the prepared polyamideimide was
220,000 g/mol, and the viscosity of the finally obtained
polyamideimide was 58,000 cps, as measured using a Brookfield
viscometer at 25.degree. C.
Comparative Example 1
A polyamideimide film having a thickness of 50 .mu.m was prepared
in the same manner as in Example 1, except that
biphenyltetracarboxylic dianhydride (BPDA) was not used, and the
mole ratio of TFMB:CBDA:6FDA:TPC was 100:20:25:55. The weight
average molecular weight of the prepared polyamideimide was 190,000
g/mol, and the viscosity of the finally obtained polyamideimide was
35,000 cps, as measured using a Brookfield viscometer at 25.degree.
C.
Comparative Example 2
A polyamideimide film having a thickness of 58 .mu.m was prepared
in the same manner as in Example 1, except that
cyclobutanetetracarboxylic dianhydride (CBDA) was not used, and the
mole ratio of TFMB:BPDA:6FDA:TPC was 100:20:25:55. The weight
average molecular weight of the prepared polyamideimide was 180,000
g/mol, and the viscosity of the finally obtained polyamideimide was
32,000 cps, as measured using a Brookfield viscometer at 25.degree.
C.
Comparative Example 3
The process was performed in the same manner as in Example 1,
except that 4,4'-hexafluoroisopropylidene diphthalic anhydride
(6FDA) was not used, and the mole ratio of TFMB:BPDA:CBDA:TPC was
100:20:20:60, however, the solution was hardened in a cloudy opaque
state, so that the viscosity and the weight average molecular
weight was not able to be measured.
Comparative Example 4
A polyamideimide film having a thickness of 55 .mu.m was prepared
in the same manner as in Example 1, except that
biphenyltetracarboxylic dianhydride (BPDA) and
cyclobutanetetracarboxylic dianhydride (CBDA) were not used, and
the mole ratio of TFMB:6FDA:TPC was 100:30:70. The weight average
molecular weight of the prepared polyamideimide was 150,000 g/mol,
and the viscosity of the finally obtained polyamideimide was 15,000
cps, as measured using a Brookfield viscometer at 25.degree. C.
Comparative Example 5
A polyamideimide film having a thickness of 59 .mu.m was prepared
in the same manner as in Example 1, except that
biphenyltetracarboxylic dianhydride (BPDA) was not used, and the
compound represented by the following Chemical Formula 4 was
further included, so that the mole ratio of TFMB:BPAF:CBDA:6FDA:TPC
was 100:10:20:15:55. The weight average molecular weight of the
prepared polyamideimide was 160,000 g/mol, and the viscosity of the
finally obtained polyamideimide was 18,000 cps, as measured using a
Brookfield viscometer at 25.degree. C.
##STR00010##
Comparative Example 6
A polyamideimide film having a thickness of 52 .mu.m was prepared
in the same manner as in Example 1, except that
biphenyltetracarboxylic dianhydride (BPDA) was not used, and
aromatic 3,4-oxydianiline (3,4-ODA) was included, so that the mole
ratio of TFMB:3,4-ODA:CBDA:6FDA:TPC was 90:10:30:15:55. The weight
average molecular weight of the prepared polyamideimide was 195,000
g/mol, and the viscosity of the finally obtained polyamideimide was
30,000 cps, as measured using a Brookfield viscometer at 25.degree.
C.
TABLE-US-00001 TABLE 1 Compositional ratio (mole ratio) TFMB
3,4-ODA BPDA BPAF TBIS-MPN TBIS-BAN CBDA 6FDA TPC Example 1 100 --
10 -- -- -- 20 15 55 Example 2 100 -- 20 -- -- -- 10 15 55 Example
3 100 -- 10 -- -- -- 5 15 70 Example 4 100 -- 15 -- -- -- 10 15 60
Example 5 100 -- -- -- 5 -- 25 15 55 Example 6 100 -- -- -- -- 5 25
15 55 Example 7 100 -- -- -- -- -- 30 15 55 Comparative 100 -- --
-- -- -- 20 25 55 Example 1 Comparative 100 -- 20 -- -- -- -- 25 55
Example 2 Comparative 100 -- 20 -- -- -- 20 -- 60 Example 3
Comparative 100 -- -- -- -- -- -- 30 70 Example 4 Comparative 100
-- -- 10 -- -- 20 15 55 Example 5 Comparative 90 10 -- -- -- -- 30
15 55 Example 6 Light UV Total light transmittance Yellow additive
(wt %) Thickness (.mu.m) transmittance (%) at 388 nm (%) index
Modulus (GPa) Example 1 -- 55 89.2 28.1 2.6 5.3 Example 2 -- 56
89.0 11.8 2.9 5.1 Example 3 -- 56 89.2 26.7 2.7 5.2 Example 4 -- 55
89.0 17.5 2.5 5.0 Example 5 -- 60 90.0 36.0 3.9 4.2 Example 6 -- 58
89.5 1.5 14.4 4.3 Example 7 0.15 50 89.7 12.0 4.3 5.2 Comparative
-- 50 89.8 69.5 2.4 4.8 Example 1 Comparative -- 58 89.2 11.3 3.6
4.5 Example 2 Comparative -- -- -- -- -- -- Example 3 Comparative
-- 55 90.0 70.2 3.2 4.5 Example 4 Comparative -- 59 90.0 58.0 2.6
4.3 Example 5 Comparative -- 52 83.93 0.7 18.7 4.8 Example 6
As shown in Table 1, it was confirmed that the Examples according
to the present invention had an excellent total light
transmittance, a low yellow index, and a high modulus. In
particular, it was confirmed that the light transmittance measured
at 388 nm was low. In particular, preferably, when the aromatic
diamine includes 2,2'-bis(trifluoromethyl)-benzidine, and the
aromatic dianhydride includes 4,4'-hexafluoroisopropylidene
diphthalic anhydride and biphenyltetracarboxylic dianhydride, the
cycloaliphatic dianhydride includes cyclobutanetetracarboxylic
dianhydride (CBDA), and the aromatic diacid dichloride includes
terephthaloyl dichloride, all of the above-described physical
properties may be well-implemented.
However, Comparative Example 1 had a high light transmittance in a
short wavelength region which was measured at 388 nm, and a low
modulus, as compared with the Examples. In addition, Comparative
Example 2 had a high yellow index, and Comparative Example 4 had a
high light transmittance in a short wavelength region which was
measured at 388 nm, and a low modulus, as compared with the
Examples. In addition, Comparative Examples 5 and 6 had a high
light transmittance in a short wavelength region which was measured
at 388 nm, or a very high yellow index, and a low modulus, as
compared with the Examples.
The polyamideimide film according to the present invention may have
excellent mechanical physical properties, simultaneously with a low
yellow index and an excellent light transmittance in an entire
wavelength region of visible light, and implement a low light
transmittance in a short wavelength region.
In particular, as the polyamideimide film may implement a high
modulus, and have a low light transmittance in a short wavelength
region, ultraviolet ray-induced damage by ultraviolet ray exposure
to a lower structure of a display including the polyamideimide film
may be prevented, and thus, the polyamideimide film may be applied
to various display fields.
Simultaneously, the polyamideimide film may significantly improve a
modulus, and implement excellent mechanical strength, thereby being
applied various fields including a display.
Hereinabove, although the present invention has been described by
the specific matters and specific exemplary embodiments, they have
been provided only for assisting in the entire understanding of the
present invention. Therefore, the present invention is not limited
to the exemplary embodiments, and various modifications and changes
may be made by those skilled in the art to which the present
invention pertains from this description.
Therefore, the spirit of the present invention should not be
limited to the above-described exemplary embodiments, and the
following claims as well as all modified equally or equivalently to
the claims are intended to fall within the scope and spirit of the
invention.
* * * * *